Many wounds can be treated by the application of negative pressure. The method of such treatment has been practiced for many years. The benefits of such treatment can include: reduction of edema; reduction of wound exudate; reduction of wound size; and stimulation of formation of granulation tissue. Existing devices and appliances for the provision of negative pressure wound therapy are complex. Such devices typically encompass a porous insert such as foam or gauze that is placed into the wound; a tube connecting the insert to a source of suction; a flexible cover draped over these components and sealed to the skin around the wound; an electrically powered suction pump; controls to operate the pump and monitor the system; containers to collect wound fluids; filters to process the materials removed from the wound; and safety systems to prevent harm to the patient and to block the escape of biological materials into the outside environment. These devices are expensive, labor intensive, and restrictive of patient mobility. The many components, particularly the seals around the insert and the tube, tend to leak. Therefore, suction must be applied either continuously or frequently.
Continuous suction is typically achieved by a vacuum pump powered by an electric motor. These systems require complex means to measure, monitor, and control the operation of the pump in order to ensure the safety of the patient. In addition, many negative pressure devices are contraindicated in the presence of necrotic tissue, invasive infection, active bleeding, and exposed blood vessels. They require the use of a porous insert (i.e., a sponge, foam, gauze, mesh, etc.) in the wound. The insert may present two problems: growth of tissue into the insert, and the harboring of infectious and/or undesirable materials in the insert. Wound tissue can grow into and around such inserts, causing adverse results to the healing process. Moreover, such inserts can retain wound fluid and microorganisms, and can therefore become contaminated and/or infected, presenting an adverse effect to the healing process. In addition, the high cost of these devices may deter or delay their use on patients.
Existing negative pressure treatment devices are labor intensive since they require the user to assemble, fit and customize a number of components. First, the user must prepare, trim, and size a porous insert of foam, gauze, mesh, or other material that will be placed in the wound. Next, the user must position a tube in the insert, and then cover the tube and insert with a material that is intended to create a leakproof seal. In practice, and as mentioned above, such compositions tend to leak, requiring the frequent application of suction in order to establish and re-establish negative pressure within the space about the wound. In addition, currently available negative pressure devices and systems block the view of the wound, making monitoring and diagnosis more difficult. Therefore, an improved device for applying negative pressure to wounds is needed.